Postoperative Critical Care of the Adult Cardiac Surgical Patient. Part I: Routine Postoperative Care. Crit Care Med. 2015;43:1477-1497. [PMID: 25962078 DOI: 10.1097/ccm.0000000000001059]

Effect of acute normovolemic hemodilution on coronary artery bypass grafting: A systematic review and meta-analysis of 22 randomized trials

BACKGROUND

Efficacy of minimal acute normovolemic hemodilution (ANH) in avoiding homologous blood transfusion during cardiovascular surgery remains controversial. Postoperative bleeding and transfusion remain a source of morbidity and cost after open heart operations. To better understand the role of acute normovolemic hemodilution (ANH) in coronary artery bypass grafting (CABG), we compared ANH with standard intraoperative care in a systematic review including a standard pairwise meta-analysis of randomized controlled trials (RCTs).

METHODS

We searched the Cochrane Library, PubMed, EMBASE, Web of Science and Chinese National Knowledge Infrastructure (CNKI) up to April 1, 2020. The primary outcome was to assess the incidence of ANH-related number of allogeneic red blood cell units (ARBCu) transfused. Secondary outcomes included the rate of allogeneic blood transfusion and estimated total blood loss.

RESULTS

A total of 22 RCTs including 1688 patients were identified for the present meta-analysis. Of these studies, 19 were about CABG with on-pump and three with off-pump. Our pooled result indicated that patients received ANH experienced fewer ARBCu transfusions, with a standardized mean difference (SMD) of -0.60 (95%CI -0.96 to -0.24; P = 0.001). The rate of allogeneic blood transfusion in ANH group was significant reduced when compared with controls, with a relative risk (RR) of 0.65 (95%CI 0.52 to 0.82; P = 0.0002). In addition, less postoperative estimated total blood loss was present, with a SMD of -0.53 (95%CI -0.88 to -0.17; P = 0.004).

CONCLUSIONS

The present meta-analysis indicated that ANH could reduce the number of ARBCu transfused in the CABG surgery setting. In addition, ANH could also reduce the rate of ARBCu transfusion and estimated total blood loss for CABG patients.

Checklist validation for care provided to patients in the immediate postoperative period of cardiac surgery

AIMS AND OBJECTIVES

We created and validated a checklist for nursing care of patients in the immediate postoperative period of cardiac surgery.

BACKGROUND

Cardiovascular diseases (CVD) account for about 30% of all deaths recorded in Brazil. There is an arsenal of clinical and surgical treatments for CVD, with a significant number of patients evolving to surgical treatment. Thus, health professionals working in the perioperative period of cardiovascular surgeries need to be updated, trained and qualified to provide adequate and safe care to patients.

DESIGN

We developed a checklist that defined essential parameters for quality care, to ensure greater agility and patient safety.

METHODS

This methodology validation study comprised two stages: checklist creation for care provided by nurses to patients in the IPO of cardiac surgery, and content validation using the Delphi method. Participants were selected through an advanced survey conducted on the Lattes Platform website of the National Council for Scientific and Technological Development. The STROBE checklist was used to guide the study.

RESULTS

Three rounds of analysis by specialists resulted in average CVIs of: 95.8% for objectivity, 97.9% for simplicity, 91.0% for clarity, 93.1% for relevance and 96.5% for variety, suggesting high agreement among specialists.

CONCLUSIONS

The checklist focused on nursing care of patients in the IPO of cardiac surgery and was validated with three topics, four categories, 16 items and 86 sub-items of care assignments to be applied in clinical practice.

RELEVANCE TO CLINICAL PRACTICE

This is a validated instrument that guides nurses' actions by admitting postoperative cardiac surgery patients to the ICU based on evidence, which provides more scientific and professional support to health teams' performance, with the objective of strengthening roles and establishing routines; thus presenting a powerful tool for planning nursing actions, providing quality care to patients, and facilitating communication between teams, thereby minimising risks.

Comparison of the proximal and distal approaches for axillary vein catheterization under ultrasound guidance (PANDA) in cardiac surgery patients susceptible to bleeding: a randomized controlled trial

BACKGROUND

The present study aimed at comparing the success rate and safety of proximal versus distal approach for ultrasound (US)-guided axillary vein catheterization (AVC) in cardiac surgery patients susceptible to bleeding.

METHODS

In this single-center randomized controlled trial, cardiac surgery patients susceptible to bleeding and requiring AVC were randomized to either the proximal or distal approach group for US-guided AVC. Patients susceptible to bleeding were defined as those who received oral antiplatelet drugs or anticoagulants for at least 3 days. Success rate, catheterization time, number of attempts, and mechanical complications within 24 h were recorded for each procedure.

RESULTS

A total of 198 patients underwent randomization: 99 patients each to the proximal and distal groups. The proximal group had the higher first puncture success rate (75.8% vs. 51.5%, p < 0.001) and site success rate (93.9% vs. 83.8%, p = 0.04) than the distal group. However, the overall success rates between the two groups were similar (99.0% vs. 99.0%; p = 1.00). Moreover, the proximal group had fewer average number of attempts (p < 0.01), less access time (p < 0.001), and less successful cannulation time (p < 0.001). There was no significant difference in complications between the two groups, such as major bleeding, minor bleeding, arterial puncture, pneumothorax, nerve injuries, and catheter misplacements.

CONCLUSIONS

For cardiac surgery patients susceptible to bleeding, both proximal and distal approaches for US-guided AVC can be considered as feasible and safe methods of central venous cannulation. In terms of the first puncture success rate and cannulation time, the proximal approach is superior to the distal approach. Trial registration Clinicaltrials.gov, NCT03395691. Registered January 10, 2018, https://clinicaltrials.gov/ct2/show/NCT03395691?cond=NCT03395691&draw=1&rank=1 .

Effect of coronary artery bypass grafting on blood pressure response to head-up tilting

Blood pressure response to head-up tilt (HUT) in 7 healthy subjects and 9 patients before and after coronary artery bypass grafting (CABG) was measured during supine and 15-min 60° HUT. Stroke volume (SV) and ejection fraction (EF) were assessed by echocardiography. Baseline mean arterial pressure (MAP) and heart rate (HR) in patients before CABG were similar to healthy subjects. MAP in patients decreased by 6 (4-9) mmHg [median (1st-3rd quartiles)] during 7-12 mmHg of HUT with decreased cardiac output (CO = SV × HR) while HR remained unchanged. MAP in healthy subjects remained unchanged during HUT with increased HR. Body weight decreased by 3.5 (2.5-3.7) kg and MAP decreased by 6 (2-13) mmHg during the last 3-min HUT while HR increased after CABG. Decreases in SV and CO during HUT disappeared after CABG. Blood pressure decreased during HUT in patients before and after CABG regardless of HR response.

Effects of cycle ergometer use in early mobilization following cardiac surgery: a randomized controlled trial

OBJECTIVE

To evaluate the effect of early use of a cycle ergometer, compared to a standard care protocol, in postoperatory in-hospital mobility following cardiac surgery.

DESIGN

A randomized controlled trial.

SETTING

Tertiary hospital in Salvador, Bahia, Brazil.

SUBJECTS

Patients submitted to elective cardiac surgery (valvular or coronary bypass surgery by sternotomy).

INTERVENTION

Patients were randomly allocated in two groups: (1) cycle ergometer training group (10-minute session) and (2) control group submitted standard physiotherapy protocol (10-minute session). Training was provided twice a day, immediately following extubation and until patient was discharged from the intensive care.

MAIN MEASURES

The primary outcome was the difference in the total number of steps recorded on the pedometer over three days. Secondary outcomes were mobility in different subgroups and the reasons that prevented individuals from walking during early cardiac rehabilitation.

RESULTS

A total of 228 participants completed the study. No significant difference was found in the total number of steps between the groups after intervention: 2183 (range: 1729-2772) in the intervention group versus 2006 (1517-2657) in the control group (P = 0.167). However, self-reports indicated better motivation in the intervention group (P = 0.044). No adverse events occurred during the study.

CONCLUSION

As a strategy for early mobilization following cardiac surgery, the use of a cycle ergometer failed to increase independent physical activity compared to a standard care protocol. Nevertheless, it was safe and could be an alternative to make rehabilitation more attractive and motivational for this patient population.

In Silico and in Vitro Conductivity Models of the Left Heart Ventricle

Ventricular Assist Devices (VADs) are used to treat patients with cardiogenic shock. As the heart is unable to supply the organs with sufficient oxygenated blood and nutrients, a VAD maintains the circulation to keep the patient alive. The observation of the patient's hemodynamics is crucial for an individual treatment; therefore, sensors to measure quantifiable hemodynmaic parameters are desirable. In addition to pressure measurement, the volume of the left ventricle and the progress of muscle recovery seem to be promising parameters. Ongoing research aims to estimate ventricular volume and changes in electrical properties of cardiac muscle tissue by applying bioimpedance measurement. In the case where ventricular insufficiency is treated by a catheter-based VAD, this very catheter could be used to conduct bioimpedance measurement inside the assisted heart. However, the simultaneous measurement of bioimpedance and VAD support has not yet been realized, although this would allow the determination of various loading conditions of the ventricle. For this purpose, it is necessary to develop models to validate and quantify bioimpedance measurement during VAD support. In this study, we present an in silico and an in vitro conductivity model of a left ventricle to study the application of bioimpedance measurement in the context of VAD therapy. The in vitro model is developed from casting two anatomical silicone phantoms: One phantom of pure silicone, and one phantom enriched with carbon, to obtain a conductive behavior close to the properties of heart muscle tissue. Additionally, a measurement device to record the impedance inside the ventricle is presented. Equivalent to the in vitro model, the in silico model was designed. This finite element model offers changes in material properties for myocardium and the blood cavity. The measurements in the in vitro models show a strong correlation with the results of the simulation of the in silico model. The measurements and the simulation demonstrate a decrease in impedance, when conductive muscle properties are applied and higher impedances correspond to smaller ventricle cross sections. The in silico and in vitro models are used to further investigate the application of bioimpedance measurement inside the left heart ventricle during VAD support. We are confident that the models presented will allow for future evaluation of hemodynamic monitoring during VAD therapy at an early stage of research and development.

Managing Vasoactive Medications Following Cardiothoracic Surgery

This article reviews the use of vasoactive medications prescribed in the postoperative management of patients who have undergone cardiac surgery. With a focus on the influence these medications have on the physiologic contributors to cardiac output and blood pressure, insight into decision making related to use, titration, and discontinuation of these medications is provided. Case studies offer vignettes to demonstrate the application of knowledge gleaned from the article.

Morbidity After cardiac surgery under cardiopulmonary bypass and associated factors: A retrospective observational study

Background

The present study aimed to assess the morbidity after cardiac surgery and identify the preoperative and intraoperative factors associated with postoperative morbidity.

Methods

A retrospective observational study was conducted including 362 adult patients aged 18–75 years who underwent open-heart surgery under cardiopulmonary bypass at Sri Jayadeva Institute of Cardiovascular Sciences and Research, Bengaluru, India, during the period from June 2016 to May 2017. Using a structured schedule, preoperative and intraoperative data were collected from the hospital's cardiac surgery database, whereas the postoperative data were collected from the intensive care unit (ICU) database and the hospital's clinical information system database.

Results

Of 362 patients, 254 (70.2%) had at least one major complication, and the most frequently occurring complication was low cardiac output state (29.8%). The ICU length of stay (LOS) was for > 2 days in 23.2% of patients, and the hospital LOS was for > 7 days in almost 60% of the patients. Multivariate logistic regression analyses revealed that gender, type of surgery, body weight, blood lactate level at ICU admission, and 12-h blood lactate level were significant predictors of complications; gender and 24-h blood lactate level were significantly associated with the prolonged ICU LOS, whereas type of surgery and 24-h blood lactate level were significantly associated with prolonged hospital LOS.

Conclusion

The appropriate patient management strategy can be tailored based on the personal attributes, surgery type, and blood lactate level for individual patients undergoing cardiac surgery to reduce the likelihood of postoperative complications, ICU LOS, and hospital LOS.

Intraoperative Mechanical Ventilation and Postoperative Pulmonary Complications after Cardiac Surgery

BACKGROUND

Compared with historic ventilation strategies, modern lung-protective ventilation includes lower tidal volumes (VT), lower driving pressures, and application of positive end-expiratory pressure (PEEP). The contributions of each component to an overall intraoperative protective ventilation strategy aimed at reducing postoperative pulmonary complications have neither been adequately resolved, nor comprehensively evaluated within an adult cardiac surgical population. The authors hypothesized that a bundled intraoperative protective ventilation strategy was independently associated with decreased odds of pulmonary complications after cardiac surgery.

METHODS

In this observational cohort study, the authors reviewed nonemergent cardiac surgical procedures using cardiopulmonary bypass at a tertiary care academic medical center from 2006 to 2017. The authors tested associations between bundled or component intraoperative protective ventilation strategies (VT below 8 ml/kg ideal body weight, modified driving pressure [peak inspiratory pressure - PEEP] below 16 cm H2O, and PEEP greater than or equal to 5 cm H2O) and postoperative outcomes, adjusting for previously identified risk factors. The primary outcome was a composite pulmonary complication; secondary outcomes included individual pulmonary complications, postoperative mortality, as well as durations of mechanical ventilation, intensive care unit stay, and hospital stay.

RESULTS

Among 4,694 cases reviewed, 513 (10.9%) experienced pulmonary complications. After adjustment, an intraoperative lung-protective ventilation bundle was associated with decreased pulmonary complications (adjusted odds ratio, 0.56; 95% CI, 0.42-0.75). Via a sensitivity analysis, modified driving pressure below 16 cm H2O was independently associated with decreased pulmonary complications (adjusted odds ratio, 0.51; 95% CI, 0.39-0.66), but VT below 8 ml/kg and PEEP greater than or equal to 5 cm H2O were not.

CONCLUSIONS

The authors identified an intraoperative lung-protective ventilation bundle as independently associated with pulmonary complications after cardiac surgery. The findings offer insight into components of protective ventilation associated with adverse outcomes and may serve as targets for future prospective interventional studies investigating the impact of specific protective ventilation strategies on postoperative outcomes after cardiac surgery.

Survival, Quality of Life, and Functional Status Following Prolonged ICU Stay in Cardiac Surgical Patients: A Systematic Review

OBJECTIVES

Compared with noncardiac critical illness, critically ill postoperative cardiac surgical patients have different underlying pathophysiologies, are exposed to different processes of care, and thus may experience different outcome trajectories. Our objective was to systematically review the outcomes of cardiac surgical patients requiring prolonged intensive care with respect to survival, residential status, functional recovery, and quality of life in both hospital and long-term follow-up.

DATA SOURCES

MEDLINE, Embase, CINAHL, Web of Science, and Dissertations and Theses Global up to July 21, 2017.

STUDY SELECTION

Studies were included if they assessed hospital or long-term survival and/or patient-centered outcomes in adult patients with prolonged ICU stays following major cardiac surgery. After screening 10,159 citations, 114 articles were reviewed in full; a final 34 articles met criteria for data extraction.

DATA EXTRACTION

Two reviewers independently extracted data and assessed risk of bias using the National Institutes of Health Quality Assessment Tool for Observational Studies. Extracted data included the used definition of prolonged ICU stay, number and characteristics of prolonged ICU stay patients, and any comparator short stay group, length of follow-up, hospital and long-term survival, residential status, patient-centered outcome measure used, and relevant score.

DATA SYNTHESIS

The definition of prolonged ICU stay varied from 2 days to greater than 14 days. Twenty-eight studies observed greater in-hospital mortality among all levels of prolonged ICU stay. Twenty-five studies observed greater long-term mortality among all levels of prolonged ICU stay. Multiple tools were used to assess patient-centered outcomes. Long-term health-related quality of life and function was equivalent or worse with prolonged ICU stay.

CONCLUSIONS

We found consistent evidence that patients with increases in ICU length of stay beyond 48 hours have significantly increasing risk of hospital and long-term mortality. The significant heterogeneity in exposure and outcome definitions leave us unable to precisely quantify the risk of prolonged ICU stay on mortality and patient-centered outcomes.

Management of Severe Bleeding in Patients Treated With Oral Anticoagulants: Proceedings Monograph From the Emergency Medicine Cardiac Research and Education Group-International Multidisciplinary Severe Bleeding Consensus Panel October 20, 2018

In this Emergency Medicine Cardiac Research and Education Group (EMCREG)-International Proceedings Monograph from the October 20, 2018, EMCREG-International Multidisciplinary Consensus Panel on Management of Severe Bleeding in Patients Treated With Oral Anticoagulants held in Orlando, FL, you will find a detailed discussion regarding the treatment of patients requiring anticoagulation and the reversal of anticoagulation for patients with severe bleeding. For emergency physicians, critical care physicians, hospitalists, cardiologists, internists, surgeons, and family physicians, the current approach and disease indications for treatment with anticoagulants such as coumadin, factor IIa, and factor Xa inhibitors are particularly relevant. When a patient treated with anticoagulants presents to the emergency department, intensive care unit, or operating room with severe, uncontrollable bleeding, achieving rapid, controlled hemostasis is critically important to save the patient's life. This EMCREG-International Proceedings Monograph contains multiple sections reflecting critical input from experts in Emergency Cardiovascular Care, Prehospital Emergency Medical Services, Emergency Medicine Operations, Hematology, Hospital Medicine, Neurocritical Care, Cardiovascular Critical Care, Cardiac Electrophysiology, Cardiology, Trauma and Acute Care Surgery, and Pharmacy. The first section provides a description of the current indications for the treatment of patients using oral anticoagulants including coumadin, the factor IIa (thrombin) inhibitor dabigatran, and factor Xa inhibitors such as apixaban and rivaroxaban. In the remaining sections, the treatment of patients presenting to the hospital with major bleeding becomes the focus. The replacement of blood components including red blood cells, platelets, and clotting factors is the critically important initial treatment for these individuals. Reversing the anticoagulated state is also necessary. For patients treated with coumadin, infusion of vitamin K helps to initiate the process of protein synthesis for the vitamin K-dependent coagulation proteins II, VII, IX, and X and the antithrombotic protein C and protein S. Repletion of clotting factors for the patient with 4-factor prothrombin complex concentrate, which includes factors II (prothrombin), VII, IX, and X and therapeutically effective concentrations of the regulatory proteins (protein C and S), provides real-time ability to slow bleeding. For patients treated with the thrombin inhibitor dabigatran, treatment using the highly specific, antibody-derived idarucizumab has been demonstrated to reverse the hypocoagulable state of the patient to allow blood clotting. In May 2018, andexanet alfa was approved by the US Food and Drug Administration to reverse the factor Xa anticoagulants apixaban and rivaroxaban in patients with major bleeding. Before the availability of this highly specific agent, therapy for patients treated with factor Xa inhibitors presenting with severe bleeding usually included replacement of lost blood components including red blood cells, platelets, and clotting factors and 4-factor prothrombin complex concentrate, or if not available, fresh frozen plasma. The evaluation and treatment of the patient with severe bleeding as a complication of oral anticoagulant therapy are discussed from the viewpoint of the emergency physician, neurocritical and cardiovascular critical care intensivist, hematologist, trauma and acute care surgeon, hospitalist, cardiologist, electrophysiologist, and pharmacist in an approach we hope that the reader will find extremely practical and clinically useful. The clinician learner will also find the discussion of the resumption of oral anticoagulation for the patient with severe bleeding after effective treatment important because returning the patient to an anticoagulated state as soon as feasible and safe prevents thrombotic complications. Finally, an EMCREG-International Severe Bleeding Consensus Panel algorithm for the approach to management of patients with life-threatening oral anticoagulant-associated bleeding is provided for the clinician and can be expanded in size for use in a treatment area such as the emergency department or critical care unit.

Microcirculation in Cardiovascular Diseases

Microcirculation is a system composed of interconnected microvessels, which is responsible for the distribution of oxygenated blood among and within organs according to regional metabolic demand. Critical medical conditions, e. g., sepsis, and heart failure are known triggers of microcirculatory disturbance, which usually develops early in such clinical pictures and represents an independent risk factor for mortality. Therefore, hemodynamic resuscitation aiming at restoring microcirculatory perfusion is of paramount importance. Until recently, however, resuscitation protocols were based on macrohemodynamic variables, which increases the risk of under or over resuscitation. The introduction of hand-held video-microscopy (HVM) into clinical practice has allowed real-time analysis of microcirculatory variables at the bedside and, hence, favored a more individualized approach. In the cardiac intensive care unit scenario, HVM provides essential information on patients' hemodynamic status, e. g., to classify the type of shock, to adequate the dosage of vasopressors or inotropes according to demand and define safer limits, to guide fluid therapy and red blood cell transfusion, to evaluate response to treatment, among others. Nevertheless, several drawbacks have to be addressed before HVM becomes a standard of care.

Stroke Volume Optimization: Utilization of the Newest Cardiac Vital Sign: Considerations in Recovery from Cardiac Surgery

The hemodynamic monitoring landscape is rapidly evolving from pressure-based and static parameters to more blood flow-based and dynamic parameters. Consensus guidelines for cardiac surgery state that the pulmonary artery catheter is neither required nor helpful in most patients. In the meantime, critical care has been searching for the alternatives to the pulmonary artery catheter and protocols for use. Best available evidence for any protocol developed suggests the inclusion of stroke volume optimization to determine fluid responsiveness. Additional strategies to using stroke volume to optimize hemodynamics, including case studies, are discussed.

Study protocol: A randomized controlled trial assessing the avoidance of endotracheal suction in cardiac surgical patients ventilated for ≤ 12 hr

AIMS

To assess the safety and efficacy of avoiding endotracheal suction in postoperative cardiac surgical patients mechanically ventilated for ≤ 12 hr.

DESIGN

A prospective, single centre, single blind, non-inferiority, randomized controlled trial evaluating the safety and efficacy of avoiding suction in uncomplicated, postoperative, adult cardiac surgical patients mechanically ventilated for ≤ 12 hr.

METHODS

Randomization will be performed on return to intensive care (ICU) with allocation to either usual postoperative care including suction or to usual care with no suction (intervention arm). The primary outcome is the ratio of partial pressure of oxygen (PaO₂ ) to fraction of inspired oxygen (FiO₂ ) (P/F) 6 hr after extubation. Pain assessments will be performed before, during and after endotracheal suction (ETS) and the patient experience will be investigated with a brief interview the following day. Ethics approval was received in October 2015.

DISCUSSION

Endotracheal suction is performed as part of airway management but has potential complications and there is little robust evidence to guide practice. This study will add to the evidence base about the need and benefit of endotracheal suction in this patient cohort.

IMPACT

As there is currently no published evidence about the safety of avoiding endotracheal suction. This study will provide the first evidence about avoidance of endotracheal suction in patients ventilated for less than 1 day. If non-inferior, the results have the capacity to change nursing practice by avoiding a potentially unnecessary procedure, it will build on the body of knowledge about the patient experience.

Reliability of three-dimensional color flow Doppler and two-dimensional pulse wave Doppler transthoracic echocardiography for estimating cardiac output after cardiac surgery

BACKGROUND

Three-dimensional color flow Doppler (3DCF) is a new convenient technique for cardiac output (CO) measurement. However, to date, no one has evaluated the accuracy of 3DCF echocardiography for CO measurement after cardiac surgery. Therefore, this single-center, prospective study was designed to evaluate the reliability of three-dimensional color flow and two-dimensional pulse wave Doppler (2D-PWD) transthoracic echocardiography for estimating cardiac output after cardiac surgery.

METHODS

Post-cardiac surgical patients with a good acoustic window and a low dose or no dose of vasoactive drugs (norepinephrine < 0.05 μg/kg/min) were enrolled for CO estimation. Three different methods (third generation FloTrac/Vigileo™ [FT/V] system as the reference method, 3DCF, and 2D-PWD) were used to estimate CO before and after interventions (baseline, after volume expansion, and after a dobutamine test).

RESULTS

A total of 20 patients were enrolled in this study, and 59 pairs of CO measurements were collected (one pair was not included because of increasing drainage after the dobutamine test). Pearson's coefficients were 0.260 between the CO-FT/V and CO-PWD measurements and 0.729 between the CO-FT/V and CO-3DCF measurements. Bland-Altman analysis showed the bias between the absolute values of CO-FT/V and CO-PWD measurements was - 0.6 L/min with limits of agreement between - 3.3 L/min and 2.2 L/min, with a percentage error (PE) of 61.3%. The bias between CO-FT/V and CO-3DCF was - 0.14 L/min with limits of agreement between - 1.42 L /min and 1.14 L/min, with a PE of 29.9%. Four-quadrant plot analysis showed the concordance rate between ΔCO-PWD and ΔCO-3FT/V was 93.3%.

CONCLUSIONS

In a comparison with the FT/V system, 3DCF transthoracic echocardiography could accurately estimate CO in post-cardiac surgical patients, and the two methods could be considered interchangeable. Although 2D-PWD echocardiography was not as accurate as the 3D technique, its ability to track directional changes was reliable.

Handgrip Strength in Preoperative Elective Cardiac Surgery Patients and Association With Body Composition and Surgical Risk

BACKGROUND

Handgrip strength (HGS) is a potential method to approximate perioperative risk in cardiothoracic surgery patients and correlates well with European System for Cardiac Operative Risk Evaluation (EuroSCORE) values. This study aimed to characterize the functional capacity in preoperative cardiac surgery patients through HGS.

METHODS

This cross-sectional study investigated patients aged 18 years or older. The collected data included surgical risk (EuroSCORE), body mass index (BMI), body composition (electrical bioimpedance), and HGS.

RESULTS

The mean age of the 278 participants was 62.1 ± 11.2 years, of whom 61.5% were male, 43.2% were overweight, and 26.3% were obese. The main types of surgery were myocardial revascularization (50%) and valve replacement (40.6%). HGS values differed between genders in all age groups (P < 0.05) and were approximately 40% lower than reference values for healthy individuals. The values differed with respect to operative risk (P = 0.003) and had a moderate positive correlation with fat-free mass (r_s = 0.435, P < 0.001), a moderate negative correlation with fat mass (r_s = -0.447, P < 0.001), and weak negative correlations with age (r_s = -0.270, P < 0.01) and EuroSCORE (r_s = -0.316, P < 0.01).

CONCLUSIONS

The HGS values of preoperative elective cardiac surgery patients were below reference values for healthy individuals, were lower in male patients, were positively correlated with fat-free mass, and were negatively correlated with fat mass, age, and operative risk. Its preoperative use in these patients is an attractive complementary method of risk assessment in clinical practice.

The prognostic accuracy evaluation of SAPS 3, SOFA and APACHE II scores for mortality prediction in the surgical ICU: an external validation study and decision-making analysis

BACKGROUND

The early postoperative period is critical for surgical patients. SOFA, SAPS 3 and APACHE II are prognostic scores widely used to predict mortality in ICU patients. This study aimed to evaluate these index tests for their prognostic accuracy for intra-ICU and in-hospital mortalities as target conditions in patients admitted to ICU after urgent or elective surgeries and to test whether they aid in decision-making. The process comprised the assessment of discrimination through analysis of the areas under the receiver operating characteristic curves and calibration of the prognostic models for the target conditions. After, the clinical relevance of applying them was evaluated through the measurement of the net benefit of their use in the clinical decision.

RESULTS

Index tests were found to discriminate regular for both target conditions with a poor calibration (C statistics-intra-ICU mortality AUROCs: APACHE II 0.808, SAPS 3 0.821 and SOFA 0.797/in-hospital mortality AUROCs: APACHE II 0.772, SAPS 3 0.790 and SOFA 0.742). Calibration assessment revealed a weak correlation between the observed and expected number of cases in several thresholds of risk, calculated by each model, for both tested outcomes. The net benefit analysis showed that all score's aggregate value in the clinical decision when the calculated probabilities of death ranged between 10 and 40%.

CONCLUSIONS

In this study, we observed that the tested ICU prognostic scores are fair tools for intra-ICU and in-hospital mortality prediction in a cohort of postoperative surgical patients. Also, they may have some potential to be used as ancillary data to support decision-making by physicians and families regarding the level of therapeutic investment and palliative care.

Effect of a Controlled Release of Epinephrine Hydrochloride from PLGA Microchamber Array: In Vivo Studies

This paper presents the synthesis of highly biocompatible and biodegradable poly(lactide- co-glycolide) (PLGA) microchamber arrays sensitive to low-intensity therapeutic ultrasound (1 MHz, 1-2 W, 1 min). A reliable method was elaborated that allowed the microchambers to be uniformly filled with epinephrine hydrochloride (EH), with the possibility of varying the cargo amount. The maximum load of EH was 4.5 μg per array of 5 mm × 5 mm (about 24 pg of EH per single microchamber). A gradual, spontaneous drug release was observed to start on the first day, which is especially important in the treatment of acute patients. Ultrasound triggered a sudden substantial release of EH from the films. In vivo real-time studies using a laser speckle contrast imaging system demonstrated changes in the hemodynamic parameters as a consequence of EH release under ultrasound exposure. We recorded a decrease in blood flow as a vascular response to EH release from a PLGA microchamber array implanted subcutaneously in a mouse. This response was immediate and delayed (1 and 2 days after the implantation of the array). The PLGA microchamber array is a new, promising drug depot implantable system that is sensitive to external stimuli.

Impact of maintenance, resuscitation and unintended fluid therapy on global fluid load after elective coronary artery bypass surgery

INTRODUCTION

Standardized protocols are provided for maintenance and replacement fluid therapy in critically ill patients. However, unintended fluid sources (analgesics, antibiotics and other drugs) are not always taken into account when prescribing intravenous fluid therapy. We evaluated the extent to which maintenance, resuscitation and unintended fluids contributed to total fluid load in elective coronary artery bypass graft patients during their ICU stay.

METHODS

Data on intravenous and oral fluid input and output were retrospectively collected from the electronic medical files.

RESULTS

Sixty patients were included. Maintenance fluids represented 1435 ± 570mL (49%) and 2214 ± 657mL (71%), resuscitation fluids 847 ± 542mL (29%) and 338 ± 559mL (11%), unintended fluids 639 ± 162mL (22%) and 576 ± 285mL (18%) respectively on day 1 and day 2. Mean oral intake increased almost fourfold (from 258mL to 1017mL) on the second day.

CONCLUSION

Postoperative maintenance and resuscitation fluids are responsible for most of the observed total fluid load on the first two days after elective coronary artery bypass graft surgery. Unintended fluid load is underestimated and has to be taken into account during fluid prescription.

Perioperative Management of the Cardiac Transplant Recipient

Management of the cardiac transplant recipient includes careful titration of inotropes and vasopressors. Recipient pulmonary hypertension and ventilatory status must be optimized to prevent allograft right ventricular failure. Vasoplegia, coagulopathy, arrhythmias, and renal dysfunction also require careful management to achieve an optimal outcome. Primary graft dysfunction (PGD) can be an ominous problem after cardiac transplantation. Although mild degrees of PGD may be managed medically, mechanical circulatory support with extracorporeal membrane oxygenation or temporary ventricular assist devices may be required. Retransplantation may be necessary in some cases.

Perioperative Echocardiographic Index of Left Ventricular Filling Pressure in Cardiac Surgery

BACKGROUND

The elevated preoperative ratio of early transmitral flow velocity to early diastolic velocity of the mitral annulus (E/e') as an echocardiographic index of left ventricular filling pressure is known to be associated with poor postoperative outcomes. We investigated the association between preoperative and postoperative E/e' elevation and clinical outcomes after cardiac operations.

METHODS

The study divided 1,353 patients who underwent cardiac operations into four groups: preoperative and postoperative E/e' ≤15 (low-low), preoperative E/e' ≤15 but postoperative E/e' >15 (low-high), preoperative E/e' >15 but postoperative E/e' ≤15 (high-low), and preoperative and postoperative E/e' >15 (high-high). Cox proportional hazard analysis was performed. Kaplan-Meier curve analysis was performed before and after propensity score matching.

RESULTS

The four perioperative E/e' categories were independently associated with 5-year mortality (hazard ratio, high-high vs low-low: 3.58; low-high vs low-low: 3.75; high-low vs low-low: 1.18). Kaplan-Meier curves showed that mortality was significantly different between the groups (log-rank test: high-high vs. low-low, p < 0.001; low-high vs low-low, p < 0.001). Postoperative intensive care unit and hospital lengths of stay, incidence of acute kidney injury, and 1-year mortality were significantly different. However, after propensity score matching, mortality and the incidence of postoperative acute kidney injury were significantly different only between postoperative E/e' ≤15 and E/e' >15, but not between preoperative E/e' ≤15 and E/e' >15.

CONCLUSIONS

Postoperative E/e' >15 was more strongly associated with mortality and acute kidney injury than preoperative E/e' >15. Measurement of the postoperative E/e' ratio may help in assessing the risk of these patients.

Improved Outcomes With Integrated Intensivist Consultation for Cardiac Surgery Patients

This study examined the impact of integrated intensivist consultation in the immediate postoperative period on outcomes for cardiac surgery patients. A retrospective cohort study was conducted in 1711 adult cardiac surgery patients from a single quaternary care center in Minnesota. Outcomes were compared across 2 consecutive 2-year time periods reflecting an elective intensivist model (n = 801) and an integrated intensivist model (n = 910). Patients under the 2 models were comparable with respect to demographics, comorbidities, procedure types, and Society for Thoracic Surgery predicted risk of mortality score; however, patients in the earlier cohort were slightly older and more likely to have chronic kidney disease ( P = .003). Integrated intensivist involvement was associated with reduced postoperative ventilator time, length of stay (LOS), stroke, encephalopathy, and reoperations for bleeding (all P < .01) but was not associated with mortality. Intensivist integration into the postoperative care of cardiac surgery patients may reduce ventilator time, LOS, and complications but may not improve survival.

Impact of Intubation Time on Survival following Coronary Artery Bypass Grafting: Insights from the Surgical Treatment for Ischemic Heart Failure (STICH) Trial

OBJECTIVE

The authors aimed to assess determinants of intubation time and evaluate its impact on 30-day and 1-year postoperative survival in Surgical Treatment for Ischemic Heart Failure (STICH) trial patients.

DESIGN, SETTING, PARTICIPANTS, AND INTERVENTIONS

A multivariable Cox proportional hazards model was used among the 1,446 surgical patients from the STICH trial who survived 36 hours after operation, in order to identify perioperative factors associated with 30-day and 1-year postoperative mortality. A multivariable logistic regression model was used to determine risk factors associated with intubation time.

MEASUREMENTS AND MAIN RESULTS

At 36 hours post-operation, 1,298 (out of 1,446) were extubated and 148 (10.2%) still intubated. Median postoperative intubation time was 11.4 hours. Among patients surviving 36 hours, a multivariable model was developed to predict 30-day (c-index = 0.88) and 1-year (c-index = 0.78) mortality. Intubation time was the strongest independent predictor of 30-day (hazard ratio [HR] 5.50) and 1-year mortality (HR 3.69). Predictors of intubation time >36 hours included mitral valve procedure, New York Heart Association class, left ventricular systolic volume index, creatinine, previous coronary artery bypass grafting (CABG), and age. Results were similar in patients surviving 24 hours post-operation, where intubation time was also the strongest predictor of 30-day (HR 4.18, c-index 0.87) and 1-year (HR 2.81, c-index 0.78) mortality.

CONCLUSIONS

Intubation time is the strongest predictor of 30-day and 1-year mortality among patients with ischemic heart failure undergoing CABG. Combining intubation time with other mortality risk factors may allow the identification of patients at the highest risk for whom the development of specific strategies may improve outcomes.

Early postoperative blood pressure and blood loss after cardiac surgery: A retrospective analysis

BACKGROUND

Increased blood loss after cardiac surgery is a risk factor for patient morbidity and mortality. Guidelines for postoperative haemodynamics management recommend normotensive blood pressure to avoid increased chest drain volumes. The aim of this study was to verify the correlation of early postoperative hypertension and blood loss in patients after cardiac surgery during the early postoperative period.

METHODS

Postoperative mean blood pressure values and chest drain volumes of 431 patients were registered by an intensive care monitoring system during first 60minutes after intensive care admission. Correlation between blood pressure and blood loss was calculated by linear regression analysis.

RESULTS

In the entire patient cohort and in various subgroup analyses (body-mass-index, type of surgery, comorbidity, emergency surgery, preoperative anticoagulation therapy) no association between early mean blood pressure >80mmHg and increased blood loss was evident in simple regression analysis. Merely, after aortic surgery a correlation of hypertension and blood loss was found. Multiple regression revealed postoperative INR values >1.5 and thrombocyte counts <100.000/nL to impact blood loss in contrast to postoperative hypertension.

CONCLUSION

Evidence for strict blood pressure management to reduce blood loss after cardiac surgery is scarce. Instead, in face of higher INR and low thrombocytes increasing postoperative blood loss, achieving and maintaining a physiological coagulation is essential.

Determinants of prolonged intensive care unit stay in patients after cardiac surgery: a prospective observational study

BACKGROUND

Prolonged intensive care unit (ICU) stay of patients after cardiac surgery has a major impact on overall cost and resource utilization. The aim of this study was to identify perioperative factors which prolong stay in ICU.

METHODS

All adult patients from a single, specialized cardiac center who were admitted to the ICU after cardiac surgery during a 2-month period were included. Demographic and clinical characteristics, comorbidities, preoperative use of drugs, intraoperative variables, and postoperative course were recorded. Hemodynamic and blood gas measurements were recorded at four time intervals during the first 24 postoperative hours. Routine hematologic and biochemical laboratory results were recorded preoperatively and in the first postoperative hours.

RESULTS

During the study period 145 adult patients underwent cardiac surgery: 65 (45%) underwent coronary artery bypass graft surgery, 38 (26%) valve surgery, 26 (18%) combined surgery and 16 (11%) other types of cardiac operation. Seventy nine (54%) patients had an ICU stay of less than 24 hours. Random forests analysis identified four variables that had a major impact on the length of stay (LOS) in ICU; these variables were subsequently entered in a logistic regression model: preoperative hemoglobin [odds ratio (OR) =0.68], duration of aortic clamping (OR =1.01) and ratio of arterial oxygen partial pressure to inspired oxygen fraction (PaO₂/FiO₂) (OR =0.99) and blood glucose during the first four postoperative hours (OR =1.02). ROC curve analysis showed an AUC =0.79, P<0.001, 95% CI: 0.71-0.86.

CONCLUSIONS

Low preoperative hemoglobin, prolonged aortic clamping time and low PaO₂/FiO₂ ratio and blood glucose measured within the first postoperative hours, were strongly related with prolonged LOS in ICU.

Effects of Ambulation and Nondependent Transfers on Vital Signs in Patients Receiving Norepinephrine

PURPOSE

To assess the safety of mobilizing patients receiving low-dose norepinephrine (0.05 μg/kg per min) by examining mean arterial pressure and heart rate before and after activity with parameters set by the physician.

BACKGROUND

Norepinephrine is a peripheral vasoconstrictor administered for acute hypotension. During activity, blood flows to the periphery to supply muscles with oxygen, which may oppose the norepinephrine vasoconstriction. The safety of mobilizing patients receiving norepinephrine is unclear.

METHODS

Heart rate, mean arterial pressure, norepinephrine dose, and activity performed were extracted retrospectively from charts of 47 cardiothoracic surgery patients during the first patient transfer to chair or ambulation with norepinephrine infusing. Mean arterial pressure and heart rate were compared before and after physical therapy (paired t tests). Differences among norepinephrine doses and physical activity levels were evaluated (Kruskal-Wallis test).

RESULTS

Forty-one of the 47 patients (87%) tolerated the activity within safe ranges of vital signs. The change in patients' mean arterial pressure from before to after activity was not significant (P = .16), but a significant increase in heart rate occurred after activity (P < .001). A Kruskal-Wallis test showed no significant difference in the norepinephrine dose and activity level (χ² = 6.34, P = .17). No instances of cardiopulmonary or respiratory arrest occurred during any physical therapy sessions.

CONCLUSIONS

Infusion of low-dose norepinephrine should not be considered an automatic reason to keep patients on bed rest.

Dexmedetomidine sedation reduces atrial fibrillation after cardiac surgery compared to propofol: a randomized controlled trial

BACKGROUND

Atrial fibrillation occurs frequently in patients following cardiac surgery and can be a cause of increased morbidity and mortality. The use of dexmedetomidine to prevent atrial fibrillation is unclear. The present study was designed to evaluate the effect of dexmedetomidine sedation on the incidence of atrial fibrillation after cardiac surgery.

METHODS

Upon arrival to the intensive care unit (ICU), cardiac surgery patients without prior atrial fibrillation or flutter were randomized to receive either dexmedetomidine (0.2-1.5 μg/kg/h) or propofol (0.3-3 mg/kg/h) open-label titrated to a target Richmond agitation-sedation scale of 0 to -3. Our primary endpoint was the incidence of postoperative atrial fibrillation, and the secondary end points were the length of ICU stay, length of hospital stay, and hospital costs.

RESULTS

Atrial fibrillation occurred in 6 of 44 patients (13.6 %) in the dexmedetomidine group compared to 16 of 44 patients (36.4 %) in the propofol group (odds ratio = 0.28; 95 % confidence interval, 0.10, 0.80; P = 0.025). The median (interquartile range) length of ICU stay in the dexmedetomidine group was significantly lower than in the propofol group (2.9 (2.4-3.5) vs 3.5 (2.7-4.5 days, P = 0.008), with a trend toward a decrease in median hospital costs (86,367 vs 77,874 Chinese yuan; P = 0.068). The incidence of hypotension was higher in the dexmedetomidine group than in the propofol group (25/44 (56.8 %) vs 13/44 (29.5 %); P = 0.017).

CONCLUSIONS

Dexmedetomidine sedation reduced the incidence of new-onset postoperative atrial fibrillation and shortened the length of ICU stay in patients after cardiac surgery compared to propofol sedation. Dexmedetomidine treatment was associated with more episodes of hypotension.

TRIAL REGISTRATION

chictr.org.cn: ChiCTR-IPR-16008231 , retrospectively registered: April 6, 2016. This trial was not prospectively registered due to a lack of importance applied to trial registration.

Systematic review of factors influencing length of stay in ICU after adult cardiac surgery

BACKGROUND

Intensive care unit (ICU) care is associated with costly and often scarce resources. In many parts of the world, ICUs are being perceived as major bottlenecks limiting downstream services such as operating theatres. There are many clinical, surgical and contextual factors that influence length of stay. Knowing these factors can facilitate resource planning. However, the extent at which this knowledge is put into practice remains unclear. The aim of this systematic review was to identify factors that impact the duration of ICU stay after cardiac surgery and to explore evidence on the link between understanding these factors and patient and resource management.

METHODS

We conducted electronic searches of Embase, PubMed, ISI Web of Knowledge, Medline and Google Scholar, and reference lists for eligible studies.

RESULTS

Twenty-nine papers fulfilled inclusion criteria. We recognised two types of objectives for identifying influential factors of ICU length of stay (LOS) among the reviewed studies. These were general descriptions of predictors and prediction of prolonged ICU stay through statistical models. Among studies with prediction models, only two studies have reported their implementation. Factors most commonly associated with increased ICU LOS included increased age, atrial fibrillation/ arrhythmia, chronic obstructive pulmonary disease (COPD), low ejection fraction, renal failure/ dysfunction and non-elective surgery status.

CONCLUSION

Cardiac ICUs are major bottlenecks in many hospitals around the world. Efforts to optimise resources should be linked to patient and surgical characteristics. More research is needed to integrate patient and surgical factors into ICU resource planning.